Mittwoch, 31. Dezember 2008

The last day of the year is a good time to bring on various spooky geopredictions, and possible future geological achievements. But there are mysteries that never should be discovered, secrets that never to be solved, welcome to “SPOOKY GEOLOGY”.

“I am forced into speech because men of science have refused to follow my advice without knowing why. It is altogether against my will that I tell my reasons for opposing this contemplated invasion of the antarctic - with its vast fossil hunt and its wholesale boring and melting of the ancient ice caps. And I am the more reluctant because my warning may be in vain.”

At the Mountains of Madness is a horror story by the American writer H. P. Lovecraft, written in February/March 1931 and originally serialized in the February, March and April 1936 issues of Astounding Stories (one of the first pulp- and horror fiction magazines).The story follows the tradition of the Cthulu-mythos - anyways presenting a more science (-fiction) approach to explain the rise and fall of the ancient god, and especially the elder ones. The story is written in first-person perspective by the geologist William Dyer, a professor from Miskatonic University (one of the institutions that possess a copy of the forbidden Necronomicon). A geological Antarctica-expedition discovers first strange fossils, eons of years older then all other signs of life on our planet, and finally a mountain range, much higher and darker then the Himalaya in the remotest corner of this frozen world. But after a carefully investigation at the borders of the mountain range of more strange fossils, contact get lost with the team, and the narrator makes his way to discover what happened at the Mountains of Madness.

Lovecraft had a lifelong interest in the exploration of the Antarctic continent. The biographer S. T. Joshi notes, that "Lovecraft had been fascinated with the Antarctic continent since he was at least 12 years old, when he had written several small treatises on early Antarctic explorers.”By the 1920s Antarctica was one of the last unexplored regions of the earth, where large stretches of territory had never seen the tread of human feet. Contemporary maps of the continent show a number of provocative blanks, and Lovecraft – as a writer- could exercise his imagination in filling them in. In fact the first expedition of Richard Evelyn Byrd took place in 1928-1930, the period just before the novella was written, and Lovecraft mentioned the explorer repeatedly in his letters, remarking at one point on "geologists of the Byrd expedition having found many fossils indicating a tropical past".Lovecraft's was not only a passionate autodidact in geology, but also in American classic literature. Most obvious literary source for At the Mountains of Madness is Edgar Allan Poe's lone novel, The Narrative of Arthur Gordon Pym of Nantucket, whose concluding section is set in Antarctica. Lovecraft twice cites Poe's "disturbing and enigmatic" story in his text, and explicitly borrows the mysterious phrase "Tekeli-li" from Poe's work. Also, a graduate student, seeing at the arrival of the expedition on the McMurdo-Sund the active volcano Mt. Erebus, cites poetry by E.A. Poe to describe the scenery.

Many of the first Lovecraft's stories involve features that appear to be supernatural, such as monsters, demons and the occult, without clear explanation from where they come, or what they are. However, Mountains appears to explain the origins of such elements like the occult symbols or to "gods" such as Cthulhu in rational terms, by terrifying scientific facts - like the fossils, or inscriptions found on cyclopic walls of a sunken city. Mountains explains many elements of the "Cthulhu Mythos" and the origin of the crinoid-like very, very old elder ones .

Lovecraft with this story not only presents a weird tale, but also insights of the geological conceptions nearby 100 years ago - worth to be known by ever geologist to dare to approach the outer limits of geomadness.

Samstag, 27. Dezember 2008

Rockglaciers are widespread in the alpine environment, where they can be regarded as reliable indicators of permafrost. Active rockglaciers are tongue-like debris masses, which show a slowly creeping and on the first view vegetation lacking surface. But anyway still some plants can be found here.In combination with geophysical methods the vegetation cover can give indications for the recent activity of rockglaciers, or help to reconstruct the temporal development where geomorphological indicators are absent.For plants they represent an ulterior challenge for colonization and growth. Surface morphology and surface instability, both resulting of the movement of the rockglacier, have been found to exert important effects on vegetation patterns developing on it. Traditional studies addressing relationships between vegetation and surface instability in the alpine environment have been carried out on scree slopes and moraines. In both habitats, plant cover and patterns of surface movement are controlled primarily by slope angle and gravity. Relationships between vegetation patterns and surface instability in arctic and alpine regions have been the object of studies focusing on community typology, growing strategies and adaptations to mechanical disturbance, root mechanical properties, and vegetation dynamics.

Along with the type of rock that composes the rockglacier, the average diameter of debris and the movement velocities influence the type of plant succession and cover that can establish.Missing fine material, and so missing colonisation niches for plant seedlings, seems to favourite plants that can grow between boulders, like Geum-species or shrubs. Active rockglaciers shows a colonisation by lichens, except for the front where pioneer species like Cerastium, Oxyria and the clubb moss Huperzia canbe found.

Cerastium uniflorum (Caryophyllaceae)

Oxyria digyna (Polygonaceae)

Huperzia selago (Lycopodiaceae)

The species poor lichen assemblage develops in the middle of rockglacier,in direction of the rooting zone the lichen cover diminishes, to lack completely in the rooting zone. Lichens can be also used for dating the rockglacier by lichenometry.A high movement causes a coarse-textured substrate; finer material fell off or between the greater, moving boulders. The resulting mechanical stress prevents the establishment of epilithic lichens on boulders.

Rhizocarpon geographicum

Brodoa intestiniformis

The vegetation patterns on active rockglaciers differed from adjacent stable areas and from inactive rockglaciers, probably because of the stressful conditions associated with substrate movement. Highly unstable sites on active rockglaciers were easily recognized by the absence of mosses and lichens. The distributional pattern of vascular plants is not strictly related to the surface instability, but depend on a combination of environmental factors, mainly substrate texture and movement intensity.

Freitag, 26. Dezember 2008

The conspicuous snowfalls since beginning of December, combined with relatively mild temperatures before and after, have triggered some rockfalls in the region of Southtyrol.The sunny weather and the resulting mild temperatures during November have prevent the freezing of the soils, and the meltwater of the snow/ice can now easily infiltrate soil and bedrock, triggering sliding and collapsing of material (numbers refers to locations on map):

5) 04.12.2008: Between the villages of Birchabruck and Gummer a rockfall with a volume of 150m3 occurred, blocking the street.8) 11.12.2008: rockfalls occurring on a footpath on the "Säbener Felsen" (Klausen)1) 16.12.2008: In the morning (3:00 a.m.), a large boulder (diameter 2m) felt on the street between the village of Latsch and Kastelbell, damaging the street, and rolling in the nearby river.2) 16.12.2006: Shortly after midday a rockfall occurred in the village of Schlanders, damaging the backside of a house.3)18-19.12.2008: A landslide with a volume of 5000m3 damages and covers the street between the village of Blumau and Breien.4) 18-19.12.2008: A rockfall with a volume of 50m3 in the same area damages heavily a protection wall, only a second wall could stop the boulders and prevent damaging of the underlying street.6) 01.12-26.12.2008: Because of high danger of rockfall and avalanches the Mendel-Pass street between Kaltern and the Province Trient is closed since the first snowfalls in the first December-week.7) 22.12.2008: Two residents were forced to leave their home in the village Stummerberg (Zillertal-Austria), the heavy snowfalls-rainfalls caused on 8:30 p.m. creeping of a part (15m broad) of the slope behind the house.

On the third day of Christmas the Geoblogosphere gave to me, a fear mongering documentary, a bunch of symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the fourth day of Christmas the Geoblogosphere gave to me, extinction, a fear mongering documentary, a bunch of symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the fifth day of Christmas the Geoblogosphere gave to me, open-access journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the sixth day of Christmas the Geoblogosphere gave to me, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the seventh day of Christmas the Geoblogosphere gave to me, volcanoes cooling climate,the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the eigth day of Christmas the Geoblogosphere gave to me, snow preventing geology-work, volcanoes cooling climate, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the ninth day of Christmas the Geoblogosphere gave to me, mapping tools for Permafrost, snow preventing geology-work, volcanoes cooling climate, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the tenth day of Christmas the Geoblogosphere gave to me, a worldwide glaciation, mapping tools for Permafrost, snow preventing geology-work, volcanoes cooling climate, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the eleventh day of Christmas the Geoblogosphere gave to me, an Accretionary Wedge, a worldwide glaciation, mapping tools for Permafrost, snow preventing geology-work, volcanoes cooling climate, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

On the twelfth day of Christmas the Geoblogosphere gave to me, twelve geology days of Christmas, an Accretionary Wedge, a worldwide glaciation, mapping tools for Permafrost, snow preventing geology-work, volcanoes cooling climate, the ghost of (65Ma) Christmas past, open-Access Journals in geology, extinction, a fear mongering documentary, a bunch of Symbols for geomorphological mapping in high mountains, and a list for christmas gifts in geology.

Dienstag, 23. Dezember 2008

The December Accretionary Wedge is hosted by Kenneth Clerk in his “Office of Redundacy”. He is asking – which scientific advancements have directly affected your interests? As first point I choose a discovery that happened not far away where I worked for my thesis. It is also mentioned in it, even is it not strictly geological, but as second point, I like to think interdisciplinary (or at least try) – and so even a archaeological discovery can be useful to understand the glacial history of a research areas:

Location of the discovery point (black rectangle) of the bronze-age mummy in the Ötztaler Alps. Blue areas represents the glacier extends in 2003, the red line the glacier extends during the Little Ice Age (ca. 1850).

The finding in the late summer 1991 of a prehistoric mummified corpse at the upper edge of the accumulation area of an alpine glacier, together with its unique set of artefacts, provided new information on the cultural development of bronze-age cultures, but also insights on the glacier dimensions during the little-known phases of major glacier shrink age that characterized the warmest parts of the Holocene. This phase is practically undocumented by glacial sediments, and is only recognizable by proxy-data like changes in pollendiagrams or dating organic materials, over- or underlying glacial or proglacial sediments.

The sudden burial of the corpse in a permanent snow cover occurred 5300–5050 cal yr B.P., indicating a significant climatic change that induced glacier expansion at the beginning of Neoglaciation.

The "Similaun" as highest peak (3597m a.s.l.) with his two glaciers, the "Similaun" in foreground, and the "Niederjoch"in background. Until ca 1970 the glaciers flowed together, but the shrinkage in the last years was notable.

The marked ablation during the summer 1991 (helped by a pronounced sunny weather and the deposition of saharian dust on the glacier ice, that diminished the albedo) of the small glacier near the Similaun Hut, in the Tyrolean Alps, brought the corpse to the surface. The preservation of the corpse was possible thanks to its location in an almost horizontal gully in the bed rock, in which it remained motionless, frozen to the ground in cold ice. This corpse is the highest prehistoric find (ca. 3280m a.s.l.) in the Alps. The discovery is also notable by the presence of a rich collection of several exceptionally preserved items of clothing and equipment. The mummy was dated by the C14-method to 4.500+-30 to 4580+-30 yr B.P., that corresponds to a calibrated age of 5300-5050 yr B.P., and resulted older then a first relative dating by the accompanying tools, especially by the bronze-axe.

The snowfield on the right of this picture represents the depression in which the corpse was found.

The small glacier that revealed the mummy lies on the northern slope of the alpine divide, east of the Finail-Spitze-mountain (3514m a.s.l.). Until the 1970, the glacier was part of the much greater Niederjoch Glacier, a composite alpine glacier that descends northward in the Nieder Valley. But only in the last 5 years the Niederjoch-glacier lost 60-100m length.During the last glacial maximum (LGM, ca. 18.000 yr), the entire area was completely ice-covered, only narrow and steep arêtes and horns protruded from the ice. In the area of the Similaun Hut sharp trimlines in a height varying from 3060m NW of the Similaun Hut to 3400m on Finail-Spitze divides the uppermost frost-shattered crests from the lower slopes, smoothed by glacial erosion. The trimline can also recognized locally as marked weathering line that separates different oxidized surfaces (the bed rock consists of Fe-rich gneiss and schist).A second trimline is marked by an abrupt change in lichen diameter (from 100mm above to 40mm below) and density. The dating by lichenometry attributes this glacier stand to the Little Ice Age (LIA), which generally corresponds to the maximum Holocene glacier elevation.Some soil horizons were found in depression between 3000 and 3215m a.s.l. and dated to 5615+-55 yr B.P. (6450-6300 cal yr B.P.) and 3885+-60 yr B.P. (4416-4158 cal yr B.P.). Similar recent soils needed at least 5 to 12 centuries for development, suggesting that the climatic conditions on the site were for a long time relative favourable and constant.The Iceman and his site reveal that between 9000 and 5000 yr B.P. the mountain glaciers were smaller than in the second half of the Holocene. About 6400 cal. yr B.P. and for several centuries after, an ice-free peripheral belt allowed the accumulation of organic matter and developments of relatively thick soils. The Iceman was killed on the site during summer, and covered by snow soon after. Until 5300 to 5050 cal yr B.P. ago, a rapid climatic change took place, producing a persistent snow cover and a glacier expansion, which conserved the body until his discovery in modern times.

The valley of Tisa, on the italian side of the Alps, the Iceman came from the Valley of Schnals (in the background the modern artificial lake on the bottom of the valley) and passed the relict rockglacier in the foreground. The modern trail passes on the left side.

Detailed information about the lifestyle and environment of the Iceman is based on both on-site and off-site data. The on-site data are represented by his clothing, the wooden artefacts, plant macro remains recovered during two archaeological excavations at the discovery site in 1991 and 1992, as well as the micro and macro fossil content of the food residue from the mummies intestines. They provide information about Neolithic edible and otherwise useful plants, the making and suitability of his equipment, prehistoric diet, the season of his death, his social status, palaeo-environment and the taphonomy of the find assemblage. Off-site data are represented by palynological and macroremains analyses of peat deposits from mires in the nearer and wider vicinity of the discovery site, which reveal the vegetation and climate history as well as human impact on the vegetation during the time of the Iceman.Both the axe shaft and the long bow were found in the vicinity of the corpse and were made of yew (Taxus baccata). The quiver was made of caprine skin and was stiffened with hazel wood (Corylus avellana). The 14 arrows were made of the wood of the wayfaring tree (Viburnum lantana). One is repaired, the front end being restored with dogwood (Cornus). The dagger handle is made from a piece of ash (Fraxinus excelsior). Its sheath was knotted from the bark of linden (Tilia).He also had with him two containers made of birch (Betula) bark, in one were found charcoal pieces wrapped in Norway maple (Acer platanoides) leaves.

Several wood species could be identified from the charcoal remains, which are interpreted as cold embers: probably spruce (Picea/Larix-type), pine (Pinus mugo-type), green alder (Alnus viridis), some Pomoideae which were probably Juneberry (cf. Amelanchier ovalis), dwarf willow (Salix reticulata-type) and elm (Ulmus). A backpack was constructed from a thick branch of hazel (Corylus avellana) bent into a U-shape, together with two coarsely-worked laths of larch (Larix decidua).All in all, the majority of wood species found with the Iceman thrive in the montane regions (valley bottoms to 1,800 m),although some subalpine (1,800-2,500 m) and alpine (above 2,500 m) species are also represented. Their ecological requirements point to the transition zone between thermophilous mixed-oak forest communities (Quercetalia pubescenti-petreae) and the montane spruce forest (Piceetum montanum). Norwegian maple (A. platanoides), European yew (T. baccata), ash (Fraxinus sp.), lime (Tilia sp.) and elm (Ulmus sp.) allow to infer a humid habitat with a mineral rich, free-draining soil and a mild winter climate. All that is similar to the present-day conditions in the woodlands found on the slopes and in gorges in the lower Schnalstal and Vinschgau in South Tyrol, where it is assumed he lived.

The Schnals-valley and his entrance in a narrow gorge - the steep walls are very exposed and sunny, so that very dry-tolerant plant species can be found here, like cactus species (Opuntia ficus-indica), yew and shrubs communities and steppe-like grass patches. On more humid slopes a larch or spruce forest develops.

So the botanical evidence seems to confirm a climate comparable to modern conditions, and implies a glacial extent similar, if not slightly minor to the present.This has very important influence on the reconstruction of past, and modern climatic and glacial development, and at last the actual discussion about climatic change.

Freitag, 12. Dezember 2008

The snow-capped, crescent-shaped Alps and Italy’s Apennines mountain chain are shown in this Envisat image. The unusual early and strong snowfall in the last days (up to 50-200cm in 24 hours) have caused blackouts and heavy traffic jams in the affected regions.

This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on 8 December 2008.

Sonntag, 7. Dezember 2008

Maybe it’s the variety on rocks that can be found on a place – from crystalline basement, to permo-mesozoic marine and terrestrial sediments to the quaternary cover:

"Once, all mountains in the reign of the Dolomite Mountains were dark peaks, with sheer rock walls, belted by dark forest and rich pastures.

Then one day, the prince of this kingdom encountered a beautiful girl, and felt in love with her. So did the girl. After some time, they decided to marry. The first time they were very happy, and when the old king died, they become king and queen. But one day the girl went sick and weak. The prince worried, and asked her was happened. The girl explained, that she was the daughter of the moon, and were missing the vast and white plains of her native kingdom – and if she did not return, she surely will die by this desire. So the prince decided to go with her and they returned to the moon. But the light on the moon blinded the poor prince, and he had return to earth. Sad and hopeless - missing his beloved- he wandered into the forest, and encountered dwarf. He told the dwarf his problem, and the dwarf responded:” Listen carefully, young prince, I’m the king of dwarfs, and my people was banished long time ago from his land, and we are searching for a new home. If you will promise, that we can live on the peaks of your kingdom, we will solve your problem.”The king gave his word. In the night the dwarf people climbed the peaks of the mountains, and begun to weave the moon light, and cover the dark peaks, so it seemed that they were covered by snow.

The next day, the king, seeing the white peaks, enjoyed, and his queen returned to earth. And so the Pale Mountains - the Dolomite-Mountains - between dark peaks came to being."

This old ladinian (from the old folks living in the valleys of the Dolomites) myth tries to explain the variety of landscapes and rocks found there. But even the geological (his)story is fascinating, ranging from sunburned deserts to swallow lagoons to a frozen wasteland.

The Alps on a geological basis comprises rocks originating from two continents: The European continent to the north with the subsequently separated Penninic units (aquamarine blue and pink in the One Geology cartography project map); and to the south the Adriatic or Apulian microcontinent, a fragment of Africa, with its Austroalpine (dark red) and Southalpine units (violet). Due the Alpine orogenesis, the various units today lie side by side in a very confined space. The diversity of rocks also causes their strongly differentiated reactions against weathering and erosion, as well as against glacial abrasion during the Ice Age – and so a reason for the pronounced diversity of the alpine landscape.

An approximate bipartition in the eastern Alps is caused by a mayor fault system, the Periadriatic Line, separating the Austroalpine in the North, predominated by metamorphic rocks, from the Southalpine, mainly magmatic and sedimentary rocks.The basement of the Southalpine unit consists predominantly of a monoton succession of quartz phyllites of the Paleozoic era.Towards the end of the Paleozoic increasing magmatic activity started, one part of the melts remained struck in 12 km depth where it solidified; the other part reached the surface and covered enormous areas with volcanic deposits. This “Permian Athesian Volcanic Group” forms a solid fundament for the Mesozoic sediments that build up the “Pale Mountains”.

Cooling joints in ignimbrite deposits of the Auer-Formation (276-274 Ma).

Abo

Just reading

SPÖTL et al.(2006):The last and the Penultimate Interglacial as Recorded by Speleothems From a Climatically Sensitive High-Elevation Cave Site in the Alps. In SIROCKO, F. et al. (ed): The climate of past interglacial. Developments in Quaternary Science 7.